Electromagnetic step-by-step mechanism



C. P; SOPER AND J. A. HALL. ELECTROMAGNETIC STEP-BY-STEP MECHANlSMiAPPLICATION FILED SEPT. 29. 1919.

1,381,514, Patented June 14,1921.

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UNITED (STATES PATENT OFFICE.

CHARLES P. SOPEIh OF MAPLEWOOD. NEW JERSEY, AND JOHN A HALL, OF BAYSIDE,

NEW YORK, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEWYORK, N.' Y., A CORPORATION OF NEW YORK. I

ELECTROMAGNETIC STEP-BY-STEP MECHANISM.

'Toallwhomitmayconcem:

Be it known that we. CHARLES P. Sornn and J OHN A. HAiIL, citizc hs ofthe United States, residing at Maplewo'od, in, the county of EssexandStat ecof New Jersey, and at Bayside, Lon Island,- in'the county ofQueens andtate of New York, respectively, have inventedcertain new anduseful Improvements in Electromagnetic Stepby-Step Mechanisms, of whichthefollowmg is a full, clear, concise; and "exact de- T isinventionrelates Step-by;step mechanisms and moreiparticu larly to means forelectrically controlling I the operation of such. mechanisms.

1 The object ofthe invent'ion is to provide an improved step-by-stepmechanism in which the full step both forward and backward is insured,not by any mechanical adjustment of springs, but rather by the movementof the. member to be moved;

Heretofore in such arrangements the movement of the actuating member hasbeen:

c'ontrolle'dfiby mechanictihmeans which although adjusted tocorrespondfwith the movement ofthe member to be .moved, nevertheless didnot cooperate with it. According tothe above object the. presentinvention contemplates an. arrangement, wherein no special adjustment isnecessary since the movement of the; actuating member is con- 'trolledby the ,movement of the actuated member. 1 I

.More specifically this invention .-comprises a magnet caly actuatedpawl adapted to step a'ratchet member forward. and a holding pawladapted to, prevent backward movement of said ratchet member. Each ofthese pawls controls contacts in the energizing circuit of the.electromagnet, said contacts being so arranged that on the forwardmovement of the ratchet. member the circuit arrangement is maintainedundisturbed until the holding pawl drops into a succeeding tooth at theend of a step. Thereupon the condition of the circuit is changed andthis changed condition '18 maintained until the" stepping pawl dropsinto a succeeding tooth at which time the mechanism 'is ready to repeatthis cycle of operations. Any desired means for closing the electricalcircuit to initiate stepping and opening it to arrest stepping may beprovided. The

to electromagnetic Specification of Letters Patent. Patented'June 14,1921. Application filed September 29, 1919. SerialNo; 327,123.v

mechanism may be employed to rotate a shaft, to advance a toothed bar,or wherever a step-by-ste'p-movement is desired;

In the drawings Figure 1 is a view in elevation of the inventionapplied-to a mechanism in which an electromagnet inattracting itsarmature actuatesa'a pawl to stepa ratchet wheel, and in retractinglitsarmature moves the pawl into'enga'gement with a succeedingtoothqn'eparatory to the next step. Fig; 2 is a view'in elevation of theinvention applied to "a mechanism in" which an electromagnetiii-attracting its armature moves a pawlbackward to engage'a tooth ofa'ratchet wheel, and in retractingits armature aotuates the pawl to stepthe ratchet wheel forward. I I

Both Figs. land 2 show the mechanisms in normal position withtheelectromagnets deenergized. The circuits for the electromagnets areindicated diagrammatically. Fig. 3 shows a portion ofthe mechanismillustrated in Fig.2 at the moment just. before the armature iscompletely attracted anew tooth. v

Referring more particularly to Fig. 1, an

and as the stepping pawl is vabout toengage electromagnet 1"is securedto a yoke 2 upon.

which is pivotally supported an armature 3; at the point 4. Contactsprings 5-, 6;? and 8 are mounted upon a -bent'overportion 9 ofthe yoke2, being insulated therefrom I and from each other in any desiredmanner.

A spring 10 retracts the armature 3 when the magnet 1 is deenergized,the retracting movement being arrested by a stop 11 fined to the frame(not shown). A stepping pawl is pivotallymounted at the end 12 ofarmature 3. The pawl 13 is held in engagement with the teeth of aratchet wheel 14 by'the pressure of spring 8 on a button 18 ofinsulating material rigidly fixed to pawl 13'. The ratchet wheel isrigidly mounted on a shaft 15 which may be rotatably supported in anydesired manner. Backward movemnt of wheel 1.4 is prevented by the end 17I of s ring 5 which acts as a holdingpawl.

en the switch 16 is closed, a circuit is completed to energize magnet 1,which circuit may be traced from grounded battery, switch 16, through,the winding of magnet 1, springs 8 and 7 to ground. Magnet 1 inattracting its armature actuates pawl 13 to step ratchet wheel 14forward, that is n springs 7 and 10- 6. thus completing a substituteenergizing circuit for magnet 1 which may be traced through springs 5and 6 in parallel with the circuits previously traced through 8. Justafter the closure of springs 5 and 6, the button 18 carried by pawl 13encounters a bent portion 19 of spring 8, thus forcing springs 7 and 8apart. The button 18 is it will hold springs 7 and 8 apart throughoutthe a'ema-inder of "the forward step of pawl 13. The ma netthus remainsenergized until the bolt ing end 17 of spring 5 passes over the edge ofthe tooth upon which it has been riding and drops into engagement withthe next tooth. Tn dropping into engagement with the next tooth. spring5 opens the circuit for magnet 1 at the contact between springs 5 and 6.and magnet 1 dccnergizes, its armature3 being under the tension ofspring until it cucounters stop 11. uring the retraction of armature 3,springs and 8 are held apart by theengagement of button 18 with spring 8until pawl 13, in dropping into engagement with the next tooth, againcloses the contact between springs 7 and 8, whereupon the cycle ofoperations described is repeated. Thus stepping continues as long asswitch 16 remains closed.

In the mechanism shown in Fig. 2, a magnet 20.is secured to a framemember 21, on which is pivotally mounted at 22 an armature 23. Armature23 is normally held in retracted position against a stop 24 hyspring 25.A lever 26 rigidly mounted on armature 23 pivotally supports at 27 acranbshapcd stepping pawl 28. Contact springs 29, 30, 31 and 32 aresecured to frame piece 21 by a screw 37 and are insulated therefrom andfrom each other. Pawl 28 is held in engagement with the teeth of aratchet wheel 34 by the pressure of spring 29 on the arm 33. and thepressure of the teeth on the nose of pawl 28 causes arm to close thecontact between springs 29 and 30 at all times except that just afterpawl 28 has ridden over the edge of a tooth and has dropped intoengagement with the next tooth. The ratchet wheel 34 is rigidly securedto a shaft which is rotatably mounted in any desired manner. Spring 31acts as a holding pawl, and is positioned so as to make con tact withspring 32 only in the position which it occupies just after spring 31has ridden over the edge of .a tooth. In other positions the pressure ofthe tooth moving under spring 31 forces it away from spring 32 so as tobreak their contact.

,en switch 36 is closed, a circuit is com- 5 is forced by the intoengagement with spring ,by the tooth over which it is facts betweensprings 29 and 30.

so positioned that retracted mechanism, a

pleted from grounded battery, switch 36, through contact springs 29, 30,31 and 32, in series, throuwb the windingof magnet 20 to ground. Itagnct 20 is energized in this circuit and attracts its armature 23.Throughout the attractive step of armature 23 the nose of the pawl 28 isforced upward passing, thereby'holding arm 33 againstspring 29 tomaintain the closed condition of the conahS this step, in contact. Fig.

wheel34 is not in motion during springs 31 and 32 remain 3 shows theposition of the pawls and contact springsnear the end of the attractivestep of armature 23. Thus the energizing circuit for magnet 20 ismaintained until the pawl 28- in dropping into engagement with the nexttooth allows spring 29 to give a clockwise rotation to the pawl28,'thereby opening the contact between springs 29 and 30. he energizingcircuit being thus broken, magnet 20 dlienergizes and its armature 23 isretracted by spring 25. Durin this retractive movement pawl 28 is moved"to the right by lever 26 to step in a clockwise direction. Spring 31 inriding over the tooth with which. it is in engagement, opens the contactbetween springs 31 and 32, so that the energizing circuit of magnet 20is maintained open atthis point until spring 31 drops into engagementwith the nexttooth.' At this time pawl 28 has completed its forward stepand closed the contact between springs 29 and 30 so that .100 thecircuit is again completed for energiz; ing magnet 20, and this cycle ofoperations continues as long as switch 36 is closed.

Thus it will be seen that in both the types ot mechanism illustrated inFig. 1, and in Fig. 2, the magnet circuit ischanged to cause a forwardstep of the ratchet wheel when the stepping pawl passes over the edge ofone tooth to drop into engagement with a new tooth, and that thisconditionof the circuit ismaintained through the forward step until theholding pawl passes over the edge of one tooth and drops into engagementwith a succeeding tooth. In each case the droppin of the holding pawlinto enga ement wit the succeeding tooth changes t e condition of thecircuit to cause backward movement of the stepping pawl preparatory tothe next s ep.

What is claimed is:

1. In an electromagnetic step-by-step ratchet member, means for stepplngsaid ratchet member forward, an electromagnetic means ztor operatingsaid stepping means, mechanical means actuated when said electromagneticmeans is rendered inoperative to restore said stepping means to normalposition, means for holding said ratchet member after ithas been steppedforward, means actuated by said stepping means in dropping intoengagement with a ratchet tooth to actuate saidelectromagneticoperatingmeans, and means actuated by said holding means in dropping intoengagement with a ratchet tooth to render inoperative saidelectromagnetic means,

2. In an electromagnetic stepping device, a ratchet member, a pawltostep said ratchet member, a pawl to hold said ratchet member after ithas been stepped, a magnet to operate said stepping pawl, a spring torestore said stepping pawl, an energizing circuit for said magnet, meansactuated by said stepping pawl when it. drops into engagement with aratchet tooth tocomplete said energizing circuit, and means operated bysaid holding pawl when it drops into engagement w1th a ratchettoothtobreak said energizing circuit to allow said spring to move saidvsteppingpawl into engagement with afresh tooth.

3. In an electromagnetic stepping device, a ratchet member, a pawl tostep said ratchet member, a pawl to hold said ratchet member after ithas been stopped, a magnet to operate said stepping pawl, a spring torestore said stepping pawl, an energizing circuit 'for said magnet, acontact member actuated by said stepping pawl when it drops intoengagement with a ratchet tooth to complete said energizing circuit, anda second contact member operated by said holding pawl when it drops intoengagement with a ratchet tooth to break said energizing circuit toallow said spring to move said stepping pawl into engagement with afresh tooth. T

In witness whereof, we hereunto subscribe our names this 23rd day ofSeptember, A. D.

CHARLES P. SOPER. JOHN A. HALL.

